Roller for road construction



Aug. 6, 1963 e. LEISTER ROLLER FOR ROAD CONSTRUCTION 2 Sheets-Sheet .1

Filed April 21, 1960 Garza/1i Lelsler 3 G. LEISTER 3,099,942

ROLLER FOR ROAD CONSTRUCTION Filed April 21, 1960 2 Sheets-Sheet 2 Zys.

i I i L fll fm emon' United States, Patent 3,099,942 ROLLER FOR ROAD CONSTRUCTION Gerhard Leister, Silixen, Lippe, Germany, assignor to Firma ABG-Werke Gesellschaft mit beschriinktcr Haftung, Hameln (W eser), Germany Filed Apr. 21, 1960, Ser. No. 23,806 Claims priority, application Germany Apr. 25,

1 Claim. (Cl. 94-50) least one of the roller units is so mounted that it is capable of lateral movement with respect to the central position on the roller supporting frame.

This basic principle of the invention opens up novel applications for the various types of road rollers. If this principle of the invention is for example applied to tandem rollers, it becomes possible to operate such rollers at will either with the rollers being aligned one behind the other or, by virtue of the lateral displacement of one of the roller bodies, with the roller bodies laterally displaced with respect to each other thereby enlarging the rolling width to twice the rolling width compared with that of the conventional tandem roller. In other words, the practical application of the principle of the invention makes it possible to increase the effective width of conventional types of rollers, in the limiting case to twice the normal width.

It is Well known that three-wheel rollers, having a relatively narrow steering roller in front and a pair of rear roller bodies overlapping the paths of the sides of the steering roller, suffer from the disadvantage that in the presence of obstructions at the sides-such as for example curb stonesthe edge portion of the road surface is rolled over by the wider rear roller unit only, so that the road metal is consolidated to a different degree, i.e. to a lesser extent in the edge portions than in those portions driven over by both roller units. This difference in the amount of consolidation of the road surface becomes particularly noticeable if the front steering roller operates as a vibration roller so that the edge strips will not be acted upon at all by roller vibrations. If in the case of such a threewheel roller the steering roller at the front were so arranged that it could be moved laterally with respect to the rest of the machine so that its side face could be aligned flush with that of the rear roller, it would become possible with such a roller also to subject the edge portion to the vibrations of the steering roller. It would thus become possible to subject the entire road surface as far as its side boundaries, i.e. including the edge portions, to a uniform consolidation.

The two examples quoted above show that the principle of lateral displacement of at least one of the roller units in the case of road rollers having a number of roller units arranged in tandem enables the road roller to be adapted largely to the site requirements in any particular case.

3,099,942 Patented Aug. 6, 1963 The lateral displacement of the selected roller units be effected in a variety of ways; the amount of force necessary for the operation can be considerably reduced if the roller unit is displaced whilst the machine travels at a low speed so that the roller unit performs a slow rolling movement.

The movement itself can be based on a simple displacement of the roller unit in a lateral direction, but a solution is considered preferable in which the roller unit concerned is so supported that it can rotate in both directions about a fixed point in the roller frame. The parallel movement of the roller body can then be obtained either by means of the steering linkage or by an automatic steering mechanism.

The invention will now be described in greater detail with reference to the accompanying drawings showing the invention applied to a three-wheel road roller of usual design, and in which:

FIGURE 1 shows the elevation, and

FIGURE 2 is a plan thereof.

The construction of the three-wheel road roller shown in the drawings includes two rear roller bodies 1 and a steering roller 2 in front; the motive power being provided in the usual manner by the engine 3 which drives the rear roller bodies 1 through the gear box 4. The rear portion of the roller frame forms the driving cab 5.

The front steering roller 2 is so supported that it can swing sideways about a pivot 6 which consists of a pin or similar component rigidly connected to the frame of the machine. To provide this sideways swinging movement there is provided a double-ended lever 7 having a bush 8 in front in which is rotatably supported the pin 9 of the steering bracket 10 of the steering roller 2. The rear end of the lever 7 is actuated by a hydraulic drive consisting of a fixed piston rod 11 supporting a movable cylinder 12; a fork 13 at the rear end of the lever embracing a pin 14 on the outside of the cylinder.

The steering roller is controlled by the handwheel 15 the movements of which are transmitted to the pin 9 through a steering rod 16, bevel gearing 17, worm 18, reduction gearing 19, 20, reversing idler 21 and gear wheel 22 integral with the pin 9. The advantage of this gear wheel transmission is the fact that when the steering roller 2 is moved laterally until it reaches its extreme position indicated at 23 in FIGURE 2 and in which it is flush with the rear roller body 1, and parallel to the rear roller bodies 1; it is possible to give the steering roller a slightly inclined position by means of the handwheel 15, which makes the lateral movement of the roller easier.

In the embodiment shown on the drawings, the steering roller 2 can be vibrated by means of a hydraulic motor 24 mounted on the roller frame and which is supplied with oil under pressure by a pump (not shown) through the pipes 25 and drives an out-of-balance shaft 27 by means of a belt 26.

To efiect lateral movement of the steering roller, suitable control mechanisms (not shown) are preferably provided in the driving cab for actuating the hydraulic drive of the lever 7 to the right or left as required. The hydraulic drive can be supplied if desired, by the same oil pump as that which supplies the motor 24, or it can be driven by a separate oil pump which in turn is driven by the engine 3.

three-wheel road roller in side In order to reduce the vibrations of the steering roller 2 with respect to the frame of the machine, the roller body may be provided with the usual flexible supports as indicated at 28.

The present invention can be applied both in connection with purely static and with vibration rollers, and also with rollers in which vibrating and non-vibrating roller bodies are combined within one road roller. In such case, it may be convenient to arrange either the vibrating roller :body or the non-vibrating roller for lateral displacement.

What I claim is:

A three-wheel power roller for street and road work comprising a frame, a pair of rear rollers mounted on the frame, a single front roller which is a steering roller, the width of the steering roller being narrower than the distance between the outer edges of the rear rollers, a steering bracket for the front roller and mounted on a pin, a lever arm connected at one end to said pin so that said bracket will swing with the front roller on the arm, said arm being pivotally supported on a vertical axle in the frame and between the ends of the arm, hydraulic means connected to the other end of the lever arm to swing the latter around its vertical axle and the front roller around its pivotal support as a unit to adjust the front roller laterally to align flush with one of the edges of the rear rollers relative to the direct-ion of movement of the power roller and means are provided connected to the bracket and the vertical axle to maintain the front roller parallel to the rear rollers relative to the rotary axes of the rollers, and means to rotate the steering bracket on its lever arm to steer the front roller relative to the frame, said means connected to the bracket and the vertical axle including a plurality of interconnected gear wheels mounted on the pin, the vertical axle and the lever arm. 

